Question

an engine develops 10 kw of power . how much time will it take to lift a mass of 200kg to a height to 40m ? what will be the potential energy of the mass at that height?

Answer 1

Power = 10 KW = 10000 W
Mass = 200 kg
Height = 40 m
$\text{Power =}\frac{\text{Work}}{\text{Time}}$

$10000=\frac{200\times 9.8\times 40}{\text{time}}$
$\text{Time}=\frac{200\times 9.8\times 40}{10000}=7.84\text{seconds}$

Potential energy = mgh
$\text{Potential energy}=200\times 9.8\times 40=78400\text{J}$